1. Field of the Invention
The present invention relates to apparatus and methods of securely latching doors to cabinets. More specifically, the invention relates to anti-theft latch mechanisms for securing vending machines.
2. Related Art
Thievery and vandalism have long been problems for cabinets containing valuable items or money, such as vending machines. In known vending machines, thieves may pry open the bottom of the door to gain access to a change box. Similarly, thieves may pry open the top of the door to gain access to bills in a dollar bill validator.
By using a crow bar or other instrument near the top or bottom of the door, the thieves gain entry by effectively causing the door to rotate about a handle-lock mechanism which is typically located in the middle portion of the door. When the bottom of the door is pried outward, the top of the door may be forced inward; similarly, when the top of the door is pried outward, the bottom of the door may be forced inward.
There are known systems of securing a door. For example, U.S. Pat. No. 3,314,703 (Fitzpatrick) discloses a panic release unit for windows in which a pressure plate causes rods to unlatch remotely located hooks from catches, thereby allowing the window to be quickly opened. U.S. Pat. No. 197,115 (Frees) discloses a lock for barn doors in which a threaded handle is unscrewed, drawing cords which are connected to upper and lower spring-loaded latches to thereby free the latches from staples in the door frame. U.S. Pat. No. 1,596,324 (Trood) employs a similar arrangement, having a lever-like handle which controls the position of a remote latch. Finally, U.S. Pat. No. 1,613,023 (Diete) discloses a door lock in Which a rotatable, key-lockable handle with a shaft is connected to chains which lift toothed latches from respective toothed catches in the top and bottom of the door frame. These patents, and all other documents cited herein, are incorporated herein by reference.
Unfortunately, none of these known systems provide adequate safeguards against theft and vandalism which are experienced in vending machines.
First, even if these systems were somehow adapted to the field of vending machines, they would not adequately prevent the latch from being shaken loose when a vandal or thief jars the machine while pulling outward on the door, thus allowing the latch to come loose from the catch and allowing the door to open.
Second, if these systems were somehow adapted to the field of vending machines, they would allow a vandal or thief to push the bottom (or top) of the door inward, thereby causing the top (or bottom, respectively) to extend outward, allowing the vandal or thief access to the interior of the vending machine.
Third, these systems involve rigid or unyielding connections between the knob or other control mechanism, and the latch. This rigid or unyielding connection can cause damage to the latch in the form of bending or breaking, thereby causing the latch to be ineffective in securing the door. Also, this rigid or unyielding connection requires the design to have much smaller tolerances, such as requiring the handle (for example, the Diete handle) to turn only a given predetermined angle, to prevent stress on the latch.
Therefore, there is a need in the art to provide an anti-theft latch mechanism especially suitable for vending machines which prevents vandals or thieves from pushing the door either inward or outward as they attempt to gain entry to the inside of the vending machine. Further, there is a need to provide a latch mechanism especially suitable for vending machines in which the control mechanism (such as a handle) is not rigidly tied to the remote latch, thereby avoiding possible damage to the latch and relaxing design criteria for the mechanism as a whole.